Telephone-exchange system.



A- E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED NOV. 14 1916.

Patented July 2,1918.

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A. E. LUNDELL. TELEPHONE EXCHANGE SYSTEM.

APPLICATION mp0 NOV. 1444915.

Patented July 2, 1918.

4 SHEETS-SHEET 2.

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Alba/4 f. Lunde/A y 'Afry A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM. APPLICATION man NOV. 14. 1916.

Patented July 2, 1918. v

4 SHEETS-SHEET 3- A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM. 7 I

APPLICATION FILED NOV. 14 I916- 1 71,33 Patented July 2,1918.

' 4 SHEETSSHEET 4.

To all whom itmay conaem:

Be it known that I, ALBEN E. LUNDELL,

ED STATES PATENT OFFICE.

arm: E. LUNDELL, or-rmw 103K, x. Y., nssrcnon 'ro wnsrmm nLEcmc, comm,

INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHOfiE-EXCHANGE svsrsm.

Patented July 2 1918.

Application and November 14,1910. Serial no. 131,202.

a citizen of the United States, residing at New'York, in the county of Bronx and State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems, .of which the following is a full, clear, concise, and exact description.

.This invention relates to an indicating a.r-'

rangement adapted to .be employed in telephone exchange systems for thepurpose of visually indicating the number of a tele phone line to an operator.

The object of the invention is to provide an indicating arrangement which may be controlled from a distant point by means of a manually operable device, such as a set of keys, and which will cause the visual indication, at an operators position, of-thc number in accordance with which such mane uallyoperated device was set.

It is an ob ect of the invention to provide an arrangement of this character which will operate in a reliable manner, which will involve the use of a comparatively small amount of apparatus, and which may per-- form its function in a small interval of time.

In accordance with a feature of the invention an indicator is provided in which the indication of a number of several digits. may be accomplished by means of a plurality of relays which are adapted to be operated in various combinations in response to currents varying in character. In accordance with such feature of the invention these relays,

are, by means of suitable impedances included in series therewith, arranged to respond to currents of diiferent characters. Thus relays are provided which are tuned to respond to frequencies of Q6, 50, 33 and 16 cycles per second, and also relays which are adapted to respond only-to direct current.

In accordance with a further feature of the invention, the indicator relays are less in number than the number indicators controlled thereby, there being ten number indicators for each digitof the number, any one of which may be actuated upon the operation of one of a set of five relays and one of a set of two. relays. By virtue of this arrangement it is only necessary to employ currents of five diifere'nt characters to select any one of ten number indicators.

Further features of the invention not specifically referred to above willappear from i the detailed specification and the claims.

These andother features of the invention Fig. 2 below Fig. 1, Fig.3 to the right of' Fig. 1, and Fig. 4 below Fig. 3, show diagrammatically a trunk circuit extending between an A and B operators positions toether with an indicating arrangement emod g the principle of the invention.

en the calling subscriber removes the I closes at its armature and contact a circuit for the line lamp 2. The operator, observing the line lamp 2, inserts the plug- 3' into receiver from .its switchhook in initiating a call, the line relay 1 is energized and the jack 4. As soon as the plug has been placed in the jack, a circuit is established for the relays 5 and 6, which may be traced from battery, through the relay 5, sleeve contact of the jack, cut-01f relay 6, to ground.

The relay 5 closes at its front contact a cir- Y cuit for the motor magnet of sequence switch 7 which may be traced from battery, through the motor magnet of sequence switch 7, sequence switch contact 8 in osition 1, front contact and armature of rel siy 5, to ground: whereupon the sequence switch 7 moves, into position 2. In position 2 the sequence switch contact 9 is closed and at its lower right contact establishes a circuit for the sender sequence switch 100, which may be traced from battery, through the motor magnet of sequence switch 100, sequence switch contact -101 in osition 1, conductor 102, sequence switc contact 9 in position 2, to ground. Sequence switch" 100 thereupon moves into position "2. In position 2 of the sequence .SW-ltCh- 100, a circuit is established for the updrive magnet 103 of the cord finder, from battery, through such updrive magnet, sequence switch contact 104: in position 2, back contact and armature of relay 105, to ground. The energization of the updrive magnet causes the movable contact 107, 108, 109 and 106', to pass over'stationary terminals one set of which are. indicated at 110, in, 112, 113 and 113, the set of stationary contacts shown being thosebrushes of the cord finder, indicated 'at.106,

call being described. As soon as the brush 109 makes contact with the contact 113, as-

quence switch 100 from battery, through v the motor magnet of such sequence switch,

contact 101 in position 2, front contact and right-hand armature of relay 105, to ground; whereupon sequence switch 100 moves'into position 3. The relay 105, however, remains energized after the sequence switch 100 leaves position 2, as at its left-hand armature and contact a substitute circuit for such relay is closed through the sequence switch contact 114 in positions 2 to 16 and byway of brush 108, contact 111 and sequence switch contact 9 in positions 2 to 11 to ground. The relay 105, when energized, also opens the energizing circuit previouslytraced for the updrive magnet 103, and thus stops the cord finder'with the movable brushes thereof in contact with the set of stationary terminals'individual to the cord shown in Fig. 1.

The operator, having ascertained the number desired from the calling subscriber, depresses the keys of the sending device, which has been associated withthe cord, in accordance with thenumber of the desired line. There may be provided ten oflice, ten thousands, ten tens,-ten units, and one starting key in the operators sending device.

These keys when depressed are mechanically locked and are released by means of suitable release magnets. However, only one key of each set is indicated on the drawing, it being assumed that the number 0 ofiice key indicated at 115 is depressed, the number 5 thousands key indicated at 116, the number 9 hundreds key indicated at 117, the number 3 tens key indicated at 118, and the number 0 units key indicated at 119; it being assumed, therefore, that the number desired is 05930. Having depressed the number keys, the operator thereupon depresses the starting key indicated at 120.

As soon as the starting key 120 is depressed a circuit is established for the ofiice re 'ster indicated at 121, thousands register in ioated at 122, hundreds register indicated at 123, tens registerindicated at 124 and units register indicated at 125. This energizing clrcuit may be traced from battery, through the various motor magnets of the registers, and thence through the right-hand armature and back contact of the cut-off relays individual to such registers, through the starting key 120, to ground. As soon as the ofiice register reaches position 0, a circuit is newness closed for the ofiice register cut-ofi relay indicated at 126, from battery, through the relay 127, cut-ofi' relay 126, contact 173 of the register which is closed in position 0, key 115, to ground. Similarly, when the thousands re r reaches position 5, a circuit is established for the thousands cut-off relay indicated at 128, through the register spring 129 in position 5; a circuit is established for the hundreds register cut-ofi' relay indicated at 130 through the register spring 131 in position 9; a circuit is established for the tens cut-off relay 132 through register contact 133 in position 3; and, finally, a circuit is established for the units cut-off relay indicated at 134 through con- 7 130, 132 and 134, to ground w hereupon the sequence switch moves from position 3 into position 5. As the sequence switch 100 reaches position 4, the relay still being energized, a circuit is ,closed for the release magnets of the various keys, which cause 100 suc release magnets to operate and restore the detpressed keys to normal. This circuit may traced from battery in parallel through the release magnets 137, 138, 139,140, 141, 142, through the sequence switch contact 143 in position 4, to the right armature and front contact of relay 105, and ground. It will be observed that the relay 127 was energized when the registers were set; therefore, if all of the depressed keys are completely restored when the sequence switch 100 passes position 4, the relay 127 will become denergized and the sequence switch 100 will not stop in position 5 but will be driven out of position 5 over a circuit which may be traced from battery, through the motormagnet of sequence switch 100, contact 136 inposition 5, back contact arid armature of relay 127. If the keys have not been restored, however, the sequence switch-100 wait in position 5 until the relay 127 becomes deenergized. Assuming, however, that the ke s were restored by the operation of the release magnets, the sequence switch 100 moves into position 6, in which position the fundamental circuit to the first selector switch, or, in this particular system disclosed, the ofiice selector, is established. Included in the fundamental 1 circuit and associated with the sender is the I relays,

. reaches'position cuit is established,- the stepping relay 144- usual stepping relay 144, and' such fundamental circuit also includes at the ofiice selector the usual line relay .(not shown). The ofiice, selector is merely indicated diagrammatically bythe brushes 10, 11 and 12, and a set of stationary contacts 13, 14, and 15. This selector may be of any well-lm'own type but is preferably of the type disclosed in the applicants Patent No. 1,168,319, and is adapted to be driven by a suitable mechanism over sets of stationary terminals to select a set of terminals individual to a trunk leading to a B operators, position. Such switches are provided with an interrupting device which is adapted, as the switch brushes move from terminal to terminal, to intermittently shunt and deenergize the stepping relay 144. A setof' counting usua ly twenty in number, which are also of well-known construction, is provided with each sending outfit, the number 0 or last pair Fig. 2 at case assumed, the number zero oflice key hav-' ing been depressed, it is'only necessary that the oflice selector, should take one step to bring the brushes thereof in contact with the trunks leading to the desired oflice. Only the last pair or No. 0 set is illustrated. Therefore, as soon as sequence switch 100 6 and the fundamental cirbecomes energlzed, and the counting relay 146 is energized over a-circuit including the ofiice register spring 147 which is, as indicated, .in position 0. This circuit may be traced from battery, through countin relay 146, register contact 147, armature an front contact 'of 144 to ground. As soon as relay 146 is energized it closes a locking circuitfor itself including counting relay 145.

This circuitmay be traced from battery,

through relay 146, armature and ffont contact thereof, relay 145, sequence switch spring 149 in position 6, 'to ground. Relay 145 is not operated in this circuit as it is short-circuited by the ground at the front contact of relay 144. When shunted in the well-known manner by the interrupter at the selector switch, relay 145 is operated and opens the fundamental circuit at its left-hand armature and contact; thus opening the circuit of the line relay at the first ofiice selector switch, stopping said selector switch, and also closing at its right-hand armature] and contactv a circuit through sequence switch contact 136 for the sequence said sequence switch out of which position it continues to means of circuits not shown, been driven to position '11, the intermediate positions of sequence of such relays being indicated in v 145 and 146. However, as in the motor magnet.

swept over relay 144 is cycles; re

switch '100 .when the sequence switch 7 has reached position 11, to drive position 6, from rotate until 7 position 17 is reached; When the selector switch is stopped, sequence switch 7 has, by] y jment bemg operated a 11 servselector reaches position 11, a circuit is established from hot tery, motor magnet of sequence switch 100,

armature and front contact of relay .145, brush 106", terminal 113?, sequence switch c0ntact'25 in position 11, to ground. The

sequence switch 100 thereupon leaves position 6 and movesto position 18. In positions 7, 9, 11, 13, 15 and 17 of sequence switch 100, and in position 11 of the sequence switch 7, ground is placed upon one side of n the trunk through the sequence switch contact 150, and a source of potential of a fre-.

determined by the set position of I quency registers is placed on the other side ofthe switch contact 136, position 6, right trunk through sequence switch contacts 151 and 152.

Included in the trunkextending to the B operators position is a step-by-step switch indicated at 300 and provided with two arms 301 and 302. This switch is adapted to be stepped around in response to the, energizae tion and de'einergiz'ation of the motor magnet 303 throu h a, pawl and ratchet mechanism operate by such motor magnet, the arrangement being such that when the magnet 303 is energized, the pawl is -moved over the teeth of the ratchet and when the magnet is deenergized the arms 301 and 302 are stepped forward one step by means of a spring acting upon Associated with the lower set of six contacts of such switch are conductors 304, 305 306, 307, 308 and 309 leading to six sets of relays which when energized in certain combinations cause the display of certain indicator lamps designated thousands indicator, hundreds indicator, tens indicator, and units indicator respectively. All ofthe u per set of contacts of the switch arm 301, except the last one, are connected together and to a conductor 310 to which is connected one side of one winding of each of the indicator relays. The relays 404, 409, 418 and 423 are tuned to respond to alternating current of 66 cycles; relays 400, 405, 410, 414, 419 and 424 are tuned: to res 0nd to alternating current of 425 are tuned to respond to alternating current of 33'cycles; relays'402, 407, 412, 416, 421 and 426- are tuned to respond toalternatin current of 16 cycles; and relays 403,

ma be tuned direct current. These relags h as .s own, sue

in any. suitable manner an "tuning is accomplished by-means-ofcon-- densers of various sizes indicated generally at 430. Each of the indicator relays is provided with a locking winding the arrangesuch that when: any relay is circuit is' closed'from battery,

the armature of such ays 401, 406, 411, 415, 4.20 and v 408, 13, 417, 422.and 427 respond only to III - 9, to ground. There throu h such locking winding by way of its rightand armature and contact to a common lead indicated at 433, and to ground at the back contact and right-hand armature of relay 311.

When the sequence switch 100 reaches position 7 with the thousands register in position 5, the following circuit is established from the source of 33-cycle alternating current, which circuitmay be traced from the generator 162 to the thousands register spring 165 in position 5, sequence switch contact 152 in position 7, brush 106, terminal 113, conductor 16, sequence switch contact 19 in position 11, brush 11, terminal 14, arm 302, conductor 304, relay 406, conductor 431, conductor 310, arm 301, terminal 13, brush 10, sequence switch contact 18 in position 11, conductor 17, terminal 112, brush 107, sequence contact 150 in position 7, to ground. The relay 406 is energized in this circuit. At the same time a circuit is established for relay 312, which may be traced from bat-- tery, relay 312, arm 301, terminal 13, brush 10, sequence switch contact 18, position 11,

conductor 17, terminal 112, brush 107, se-

quence switch contact 150 to ground. As the relay 312 is connected to the first six contacts swept over by arm 301, such relay will be energized over contact 150 in positions 7, 9, 11, 13, 15 and 17 of sequence-switch 100. The relay 312 closes at its armature and contact a circuit for the magnet 303, which magnet attracts its armature. As soon as sequence switch 100 leaves position 7, the circuit previously traced being opened at contact 150, the relay 312 is denergized,

causin the denergization of the ma et 303, w ich causes the switch 300 to step 111130 its second position. The relay 406, however, is maintained energized over a locking circuit from battery through right-hand winding of relay 406, right armature and contact of such relay to conductor 433, and from thence to the armature and back contact of relay 311, to ground.

When the sequence switch 100 reaches position 9 a circuit is closed from the source of 50-cycle alternating current,'which circuit ma be traced from the generator 161, hundre s register contact 166 in position 9, thousands register contact 167 in position 5, sequence switch contact 151 in position -9, brush 106, terminal 113, conductor 16, sequence switch contact 19 in osition 11, brush 11, contact 14, arm 302 0 in position 2, conductor 305, relay 400,. conductor310, arm 301 in position 2, terminal 13, brush 10, sequence switch contact 18 in position 11, conductor 17 contact 112, brush 107, sequence switch-s ring. 150 in position ay 400 is energized in this circuit. Relay 400 is locked at its right armature and contact. The relays 400 and 406 remain locked up until similar reswitch 300 lays in the tens and units indicators have been selected and in fact until the called subscriber has answered. The lamps of the source of 66-cycle alternating current over the trunk line to the indicator, which circuit may be traced as follows: from the generator 160, 100s register contact 168 in position 9, sequence switch contact 152 in position 11, brush 106, terminal 110, conductor 16, sequence switch contact 19 in position 11, brush 11, terminal'14, arm 302, conductor 306, relay 409, conductor 432, conductor 310, arm 301, terminal 13, brush 10, contact 18 in position 11, terminal 112, brush 107, sequence switch contact 150 in potion 11 to ground. The relay 312 is also energized at this time through sequence switch contact 150. Relay 409 closes at its right armature and contact a locking circuit for itself by way of the conductor 433. As soon as the sequence switch 100 leaves position 11, relay 312 is denergized, thus permitting the magnet 303 to fall back, such magnet having been ener ed in response to the energization of re ay 312. Due to the deenergization of magnet 303 the switch arm 301 is stepped into its fourth position. When the sequence switch 100 moves into position 13, the 10s register being in position 3, a circuit is established from the source of sixteen cycle alternating current by way of the trunk line to the indicator, which circuit may be traced as follows: from the position 3, sequence switch contact 152 in position 13, brush 106, terminal 113, conductor 16, sequence switch contact 19 in position 11 brush 11, terminal 14, arm 302, conductor 307, relay 421, conductor 434, conductor 310, arm 301, terminal 13, brush 10, sequence switch contact 18 in osition 11, conductor 17 terminal 112, bru 107, sequence switch contact 150, in position 13 to ground. The relay 312 is energized at this time through sequence switch contact 150 in osition 13 and establishes a circuit-from t e magnet 303. The magnet 421 when energized in the circuit just traced closes a locking circuit for itself by way of its right-hand armature eaves position 11, rela 312 becomes deiin 'ergized and consequent y the magnet 303 is denergized, stepping the switch 300 into position 5.

When the sequence switch 100 reaches position 15, the 10s register being in position 3 and the units register in position 0, a circuit is established from a source of 33-cycle alternating current by way of a trunk line to the indicator, which circuit may be traced from generator 162, units register contact 17 0 in position 0, 10s register contact 171 in position 3, sequence switch contact 151 in position 15, brush 106, terminal 113, conduc-v tor 16, sequence switch contact 19 in position 11,brush 11,terminal 14, a-rm 302, conductor 308, relay 415, conductor 434, conductor 310, arm 301, terminal 13, brush 10, sequence switch contact 18 in position 11, conductor 17, terminal 112, brush 107, sequence switch contact 150 in position 15 to ground. Relay 312 is energized at this time through sequence switch contact 150 in positlon 15. When the sequence switch 100 leaves position 15, the relay 312 is deenergized, thus deenergizing the ma et 303, which steps the arms of the switch 300 into position 6.

When the sequence switch 100 reaches position 17 a circuit is established over the trunk to the indicator which may be traced from the source of direct current 164, .units register spring 172 in position 0, sequence switch contact 152 in position 17 brush 106,

terminal 113, conductor 16, sequence switch contact 19 in position 11, brush 11, terminal 14, arm 302, conductor 309, relay 427, to ground. Relay 312 is also energized at this time over sequence switch contact 150 causing the energization of the magnet 303. Relay 427 closes at its right-hand armature and contact a locking circuit for itself by way of the conductor 433. As soon as the sequence switch 100 leaves position 17, relay 312 is denergized, deenergizing the magnet 303 and stepping the arms of the switch 300 into their seventh or through posltlon. When the sequence switch 100 reaches position 18, a sequence switch contact 176 is closed, establishing a circuit for the downdrive magnet of the cord finder which returns the cord finder to normal. As soon as the cord finder reaches its normal position the off-normal spring 175 is closed, and sequence switch 100 is driven into its normal nected from the trunk, may be used for association with another trunk or cord in set. ting up another number. As soon as the switch 300 reaches its seventh osition or final position, a circuit is esta lished for the high-resistance winding of the relay 328, which circuit may be traced from battery through the winding of repeating coil 20, supervisory relay 21, contact 19 in position 12, brush 11, terminal 14, arm 302 winding of the repeating coil 314, left-hand winding of relay 328, winding 315 of the repeating coil, arm 301, terminal 13, brush 10, contact 18 in position 12, winding 22 of the repeating coil to ground. Relay 328 being energized establishes a circuit from battery through the signal lamp 316, armature and contact of relay328, lower armature and back contact of relay 317, relay 313 to ground. The energization of the relay 313 establishes circuits for the various lamps of the indicator as determined by the locked up mdicator relays. Remembering that the relays 400, 406, 409, 415, 421 and 427 are locked up, the following circuits will be established. From battery 440 through the left-hand armature and upper contact of relay 400, through the lamp 5 of the thousands indicator, left armature and front contact of relay 406, conductor 444 to armature and contact of relay 313 to ground. The No. 5 lamp of the thousands indicator is thus displayed. A circuit is also established from ture and front contact of relay 409 to conductor 444, armature and contact of relay 313 to ground. The No. 9 lamp of the hundreds indicator is thus displayed. A circuit is also established from battery 442, left armature and upper contact of relay 415, No. 3 lamp of the tens indicator, left armature and contact of relay 421 to conductor 444, armature and contact of relay 313 to ground. The No. 3 lamp of the tens indicator is thus illuminated. A circuit is also established from battery 442, left-hand armature and lower contact of relay 415, No. 0 lamp of the units indicator, left armature and contactof relay 427, conductor 444, armature and contact of relay 313 to ground.

The operator having observed the number indicated by the indicator, inserts the plug 323, individual to the trunk indicated by the lamp 316, into the jack 324 of the desired line. As soon as the plug is inserted in the jack after the usual preliminary testing, a circuit is established from battery 321 through lamp 316, relay 317, sleeve of the plug 323, sleeve of the jack 324, cutoff relay 322 to ground. The ener 'zation of the relay 317 over this circuit esta lishes a circuit for the relay 318, which maybe traced from batmy 327, armatures and back contacts of re-' lays 320 and 311, relay 3l8, upper contact iso and lower armature of relay 317, armature and contact of relay 328, through relay 317, sleeve of plug 323, sleeve of jack 324, cutoff relay 322 to ground. Battery 325 in this circuit shunts the battery 321 and extinguishes the lamp 316. Relay 317 in its lower armature opens the circuit previously traced for relay 313, causing the release of such relay and the consequent extinguishing of the indicator lamps. The relay 318 operating establishes the ringing circuit and connects a source of ringing current indicated at 326 to the called line. When the called subscriber answers, the ringing cut-ofi' relay 320 and the supervisory relay 319 are energized. When the relay 320 is energized the shunt is. removed from relay 311, permitting it to energize. Relay 311 at its right-hand contact and armature opens locking circuits of the selecting relays and also at its left armature and contact short-circuits relay 318. Relay 319 when operated cuts in the low-resistance winding of the relay 328, which lowers the resistances of the circuit previously traced for relay 328 so that the supervisory relay 21 of the A operators position will operate and display the usual supervisory lamp,not shown, at such A operators position. The operations of supervision and of disconnect will not be described as they form no part of the present invention.

What is claimed is:

1. In a telephone exchange system, an indicatin arrangement comprising electroresponsive devices tuned to respond to currents of difierent frequency, a control circuit, manually controlled means for impressing combinations of currents of difi'erent frequencies on such control circuit to operate such electro-responsive devices in diflerent combinations, indicating devices, a plurality of which are adapted to be simultaneously displayed in response to the operation of a particular combination of such eleotro-responsive devices.

2. In a telephone exchange system, a number indicating device, comprising a set of ten indicators for each digit of the maximum number it is desired to indicate, tuned electro-responsive devices less in number than said indicators, manually controlled means for energizing such electro-responsive devices in various combinations, and a circuit for each indicator controlled by a pair of such electro-responsive devices.

3. In a telephone exchange system, an indicating arrangement comprising a plurality of digit indicators, each including a plurality of number indicators, a set of selecting relays individual to each digit indicator, additional sets of selecting relays common to a plurality of digit indicators, means for selectively energizing such selecting relays, and means controlled by a selecting relay of a set individual to a digit indicator and by a selecting relay of a set common to a plurality of digit indicators to cause the operation of a number indicator individual to such digit indicator.

4. In a telephone exchange system an indicating arrangement comprising a plurality of digit indicators, each comprising a plurality of number indicators, a plurality of sets of tuned electro-responsive devices for controlling such digit indicators, means for impressing currents of difierent frequencies on such control circuit to selectively operate such electro-responsive devices, and means also operated over the said control circuit to cause the successive association of such control circuit with a plurality of such sets of electro-responsive devices.

5. In a multi-ofiice telephone exchange system, calling and called lines, a final connector operators position, means for extending a calling line thereto over a trunk line, a device for indicating the number of a called line at said final connector operators position, a plurality of sets of tuned selecting relays for controlling such indicating device, manually controlled means at another operators position for impressing currents of different characteristics over one side of the trunk to selectively operate such selecting relays, and a step-by-step switch controlled over the other side of the trunk for successively associating such sets of selecting relays with the trunk.

In witness whereof, I hereunto subscribe my name this 13th day of November, A. D.

ALBEN E. LUNDELL. 

